What is A Moisture Meter?
Moisture meters are used to measure the percentage of water in a given substance. This information can be used to determine if the material is ready for use, unexpectedly wet or dry, or otherwise in need of further inspection. Wood and paper products are very sensitive to their moisture content. Physical properties are strongly affected by moisture content. Dimensioning also changes with moisture content. A plant moisture meter is a handy gadget to measure humidity in the soil. This device helps prevent overwatering or underwatering plants. Usually it has a scale of 1 to 10, with 1 being most dry and 10 being most wet. Most meters also have a color range composed of red, green and blue. Moisture meters are not expensive and can check plant moisture instantly.
How does work a Moisture Meter?
- Timber and Boards
- Moisture meters are hand-held devices that monitor the percentage of moisture in wood. These type of meters are a valuable aid not only for the processors of wood products such as mill sawyers and cabinetmakers, but the home shop woodworker as well. The small moisture meter can reveal if a board or wood product has too much moisture in the material. A heavy amount of moisture can mean that the piece may not fit correctly in a tight joint or expensive work piece. Mill sawyers use a moisture meter to identify certain logs that are properly cured for cutting into expensive boards. The mill can also use the moisture meter to tell them if the drying process is on schedule as in large heated kilns for removing moisture from stacks of lumber.
Moisture and Electricity
- Electrical power is easily conducted through a moist or wet environment. When wood fibers contain moisture it can also conduct an electrical signal or voltage. This allows the moisture meter to act as a signal generator. The signal generator will output a small voltage into the wood fibers. The small voltage is typically supplied by a battery. The moisture meter contains an internal circuitry much like an ohmmeter. The ohmmeter reads the amount of resistance that an electrical circuit may employ in conducting electricity. Resistance is the opposing force to efficiently conducting electricity. The moisture meter will send a small voltage into the piece of wood being tested. The voltage is conducted into the piece of wood through two very sharp pins. These pins are set a specific distance apart from each other and when the test button is pushed the meter can read the resistance between these two pins. The resistance of the wood fiber circuit is then transferred to an indicator.
LCD or Analog
- The indicator can be in the form of an LCD screen or a simple analog type meter. The LCD screen may give a numerical display as to how much moisture in that particular piece of wood. The analog meter will deflect a needle to a corresponding number on the face. These numbers will correspond to the percentage of moisture in the wood fibers. Large boards may have to be tested in a number of locations as the small pins are generally one inch apart from each other. This means that the meter is only reading that small portion of the boards moisture content. Moisture meters range in price from below $50 to units that can be tied to a laptop computer for thousands of dollars. Regardless of the cost, all moisture meters will give a reading as to the amount of moisture that is contained in a piece of wood.
How To Use Moisture Meter?
1-Pick a device. Moisture meters come plain or fancy. They can check moisture, light, soil acidity and other factors. A plain moisture meter is easiest to use for quick plant checks. Choose one that measures instantly and needs no batteries. 2-Use it to check indoor plants. Hold the head or gauge end of the meter. The pointed end is the probe. Insert the probe into the soil about three-quarters down into the pot. This measures the soil moisture at the roots. 3-Enter the red zone. Some plants need dry soil. Cactus, snake plant and other low water plants are easily killed by overwatering. Their soil moisture should be low or in the red zone. 4-Go for the green. Most plants need moderately humid soil. These include azaleas, begonias, ficus and philodendrons. Their soil humidity should be in the meter's green zone. If the meter is in the red, the plant is ready for water. If the meter is in the blue zone, the soil is too wet. Do not water again until the plant's roots show red or green. 5-Sing the blues. Some plants, such as ferns, need more water. While most plants should not be in the blue zone, which is too wet, ferns should be more in the green-blue zone than the red-green zone. 6-Walk outdoors. The moisture meter is handy for checking outdoor plants and shrub water. It is especially helpful if the plants have drip irrigation. If you think the emitters have clogged or are not putting out the right amount of water, use the moisture meter to check some places around the plant 7-Monitor frequently. Use the meter to spot-check your plants. Do not leave the meter in the plant for long. Wipe off the probe and keep the moisture meter dry and clean.